This renewal of our Aging Clinical Research Center (ACRC) reflects the continuing commitment of the Department of Psychiatry and Behavioral Sciences at Stanford to the study of Alzheimer's Disease (AD). Our Center focuses on factors associated with rate of decline in AD patients. We feel that examining issues such as the role of caregiver depression, sleep disorders, and other medical and psychiatric problems in the overall decline of AD patients may lead to treatment interventions that reduce overall disability, need for institutional care, and family hardship. Furthermore, we feel that neuropathological, neurochemical, in vivo neuroimaging, and neuropsychological studies and their relations to rate of decline could delineate subtypes of AD which could lead to insights into etiology. This is a "Core Center," defined as a Center that primarily provides Core research functions rather than directly funds large research projects. The main Cores are: 1. Administrative Core 2. Biostatistics/Data Management Core 3. Clinical Core 4. Assessment Cores, which examine the Clinical Core's AD patients from six complementary perspectives: 4a. Neuropsychology 4b. Neuroimaging Core 4c. Sleep Core 4d. Psychosocial Core 4e. Neurochemistry Core 4f. Neuropathology Core